Trypanocidal activity of the aqueous leave extract of Holarrhena Africana (Apocynaceae)

This study evaluated the trypanocidal activity of aqueous extracts of leaves of young Holarrhena africana. The trypanocidal activity was evaluated by treatment of mice infected with Trypanosoma brucei brucei at the peak of infection. The aqueous extract was administered intraperitoneally for 5 consecutive days with varied doses (100, 200, 400 mg/kg weight). Treatment with the extract led to significant reduction in the level of parasitaemia in infected mice though relapse of parasitaemia occurred later. Parasite clearance by the extract was observed to be dose-dependent, the maximal effects being attained at the dose of 400 mg/kg body weight. There were also significant improvements in the packed cell volume and reduction in the severity of clinical sign / symptom of trypanosomiasis in the treated groups during and after administration of extracts. A determination of the LD50 in acute toxicity studies showed that the extract was relatively safe at very high doses.